Phasianotrochus bellulus, common name the necklace shell, is a species of sea snail, a marine gastropod mollusk in the family Trochidae, the top snails.

The solid, imperforate, acute shell has an elongate-conic shape.

It is polished, grayish or pinkish, with a few spiral orange lines, two on the penultimate whorl.

The interior of the aperture is more coarsely sulcate than in other species, showing only about 6 folds.

The outer and basal lips have a slight submarginal porcellaneous subdentate thickening, which stops a little space short of the upper termination of the outer lip,[3] This marine species is endemic to Australia and occurs in the shallow subtidal zones off Victoria, Southwest Australia and Tasmania.